I'm sure I'm not the first guy to figure this out, and so at the risk of repeating knowledge:
Finally got around to installing a car seat (http://www.britaxusa.com/car-seats/frontier-85) in my 500. Since our cars don't have the LATCH system, I was just going to use the lap belt and tighten using the Mighty-Tite seat belt tightener (http://www.amazon.com/Sunshine-Kids-10001-Mighty-Tite/dp/product-description/B000056JHP). But I just couldn't get it tight enough to feel good about the installation.
So I removed the bottom seat cushion and took a look at if there was any way to retrofit a LATCH system in there. In my Porsche, I had done something similar by using race belt mounts for the rear seats (http://www.bkauto.com/porsche/r9003.php, install thread here: http://forums.rennlist.com/rennforums/993-forum/533634-britax-child-seats-measurements.html). Since my wife really doesn't like me taking my kids in the back of the Porsche (discussion topic for another day), I took the brackets and installed them into the 500. Only issue now was that the seat cushion won't fit over them, so I just installed the car seat without it. Sits pretty low now but the LATCH system is functional and can really cinch it down.
Finally got around to installing a car seat (http://www.britaxusa.com/car-seats/frontier-85) in my 500. Since our cars don't have the LATCH system, I was just going to use the lap belt and tighten using the Mighty-Tite seat belt tightener (http://www.amazon.com/Sunshine-Kids-10001-Mighty-Tite/dp/product-description/B000056JHP). But I just couldn't get it tight enough to feel good about the installation.
So I removed the bottom seat cushion and took a look at if there was any way to retrofit a LATCH system in there. In my Porsche, I had done something similar by using race belt mounts for the rear seats (http://www.bkauto.com/porsche/r9003.php, install thread here: http://forums.rennlist.com/rennforums/993-forum/533634-britax-child-seats-measurements.html). Since my wife really doesn't like me taking my kids in the back of the Porsche (discussion topic for another day), I took the brackets and installed them into the 500. Only issue now was that the seat cushion won't fit over them, so I just installed the car seat without it. Sits pretty low now but the LATCH system is functional and can really cinch it down.
